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BASCOM AVR, help reference (2007).PDF

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In QB/VB you can use seek to make the file bigger. When a file is 100 bytes long, setting the file pointer to 200 will increase the file with 0 bytes. By design this is not the case in AVR-DOS.

SELECT-CASE-END SELECT

Action

page -625-

Executes one of several statement blocks depending on the value of an expression.

Syntax

SELECT CASE var

CASE test1 : statements [CASE test2 : statements ] CASE ELSE : statements

END SELECT

Remarks

Var	Variable to test the value of
Test1	Value to test for.
Test2	Value to test for.

You can test for conditions to like:

CASE IS > 2 :

Another option is to test for a range :

CASE 2 TO 5 :

See also

IF THEN

Example

'-----------------------------------------------------------------------------
------------	: case.bas
'name	: case.bas
'copyright	: (c) 1995-2005, MCS Electronics
'purpose	: demonstrates SELECT CASE statement
'micro	: Mega48
'suited for demo	: yes
'commercial addon needed	: no

'-----------------------------------------------------------------------------

------------

$regfile = "m48def.dat"	' specify the used
micro	' used crystal
$crystal = 4000000	' used crystal
frequency	' use baud rate
$baud = 19200	' use baud rate
$hwstack = 32	' default use 32
for the hardware stack	' default use 10
$swstack = 10	' default use 10
for the SW stack	' default use 40
$framesize = 40	' default use 40
for the frame space
Dim I As Byte	'dim variable
Dim S As String * 5 , Z As String * 5

page -626-

Input "Enter value (0-255) " , I

Select Case I

Case 1 : Print "1"

Case 2 : Print "2"

Case 3 To 5 : Print "3-5"

Case Is >= 10 : Print ">= 10"

Case Else : Print "Not in Case statement"

End Select

Loop

End

'note that a Boolean expression like > 3 must be preceded 'by the IS keyword

SET

Action

Set a bit to the value one.

Syntax

SET bit

SET var.x

Remarks

Bit	Bitvariable.
Var	A byte, integer, word or long variable.

XBit of variable (0-7) to set. (0-15 for Integer/Word) and (0-31) for Long

See also

RESET , TOGGLE

Example

'-----------------------------------------------------------------------------
---	: boolean.bas
'name	: boolean.bas
'copyright	: (c) 1995-2005, MCS Electronics
'purpose	: demo: AND, OR, XOR, NOT, BIT and MOD
'suited for demo	: yes
'commercial addon needed	: no
'use in simulator	: possible

'-----------------------------------------------------------------------------
---	' specify the used
$regfile = "m48def.dat"	' specify the used
micro	' used crystal
$crystal = 4000000	' used crystal
frequency	' use baud rate
$baud = 19200	' use baud rate
$hwstack = 32	' default use 32

page -627-

© MCS Electronics, 1995-2007
for the hardware stack	' default use 10
$swstack = 10	' default use 10
for the SW stack	' default use 40
$framesize = 40	' default use 40
for the frame space
Dim A As Byte , B1 As Byte , C As Byte
Dim Aa As Bit , I As Integer
A = 5 : B1 = 3	' assign values
C = A And B1	' and a with b
Print "a AND c = " ; C	' print result
C = A Or B1	'also for or
Print "a OR b1 = " ; C
C = A Xor B1	' and for xor
Print "a XOR b1 = " ; C
A = 1	'not
C = Not A	'not
Print "c = NOT a " ; C
C = C Mod 10
Print "c MOD 10 = " ; C
If Portb.1 = 1 Then
Print "Bit set"
Else
Print "Bit not set"
End If
Aa = 1	'use this or ..
Set Aa	'use the set
statement
If Aa = 1 Then
Print "Bit set (aa=1)"
Else
Print "Bit not set(aa=0)"
End If
Aa = 0	'now try 0
Reset Aa	'or use reset
If Aa = 1 Then
Print "Bit set (aa=1)"
Else
Print "Bit not set(aa=0)"
End If
B1 = 255	'assign variable
Reset B1.0	'reset bit 0 of a
byte variable	'print it
Print B1	'print it
Set B1.0	'set it
Print B1	'print it
End

page -628-

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Function	_FileSeek
Calls
Input	r24: filenumber	X: Pointer to Long-variable, which gets the
		result
Output	r25: Errorcode	C-Flag: Set on Error

Statement	_FileSeekSet
Calls
Input	r24: filenumber	X: Pointer to Long-variable with the position
Output	r25: Errorcode	C-Flag: Set on Error

Open "test.biN"for Binary As #2	' write a byte
Put#2 , B	' write a byte
Put#2 , W	' write a word
Put#2 , L	' write a long
Ltemp = Loc(#2) + 1	' get the position
of the next byte	' store the
Print Ltemp ; " LOC"	' store the
location of the file pointer
Print Seek(#2) ; " = LOC+1"
Close #2
'now open the file again and write only the single
Open "test.bin" For Binary As #2	' set the
Seek#2 , Ltemp	' set the
filepointer	' change the
Sn = 1.23	' change the
single value so we can check it better	'specify the file
Put #2 , Sn = 1	'specify the file
position
Close #2